Eight months since his inauspicious debut, Mr. Iron Hands was Mr. Iron Man compared to San Francisco's other rookies. The only undrafted rookie to make the 53-man roster, Celek logged 105 snaps, more than the six draft picks still with the team.

Did Celek imagine he'd play more than rookie running back LaMichael James, who was an All-American at Oregon while Celek toiled in anonymity at Michigan State? Celek, who had three of his 14 career catches as a senior, smiled before turning serious when posed that question Friday.

"I don't want to say I didn't see it coming because I'm always working for it," Celek said. "I'm just really happy that happened."

Looking ahead to the 2013 season, there is some evidence that Celek could move from feel-good story into an offensive factor, particularly if Walker, the No. 2 tight end and a pending free agent, signs elsewhere in the offseason.

A left tackle in high school, Celek, 6-foot-5 and 252 pounds, made the team thanks largely to his blocking prowess. However, he also possesses above-average speed for his size, and quarterback Alex Smith was initially struck by how his wingspan made him an inviting target.

"The first thing that jumped out to me was his catch radius," Smith said. "He's got long arms and is such a big target. And he catches with his hands really well."

Well, now he does.

Celek (four catches for 51 yards on the season) had a season-high 29 snaps in a 42-13 loss at Seattle on Dec. 23 after Davis left with a concussion in the first quarter. He responded with two catches for 41 yards, including a difficult 35-yard grab over the middle.

The catch was a reminder of how much Celek has developed as a pass catcher since his college days. Earlier this season, he offered this scouting report of himself at Michigan State: "I didn't run that good of routes. And I didn't catch very well."

The secret of his progress isn't much of a mystery. He has spent countless hours catching balls after practice, dedication that doesn't surprise Mark Staten, Celek's offensive line coach for three years at Michigan State. In the summer, Staten was hoping Celek could make the 49ers' practice squad.

"To make the regular squad?" Staten said. "That's just his work ethic. That's just the Celek work ethic that we were fortunate to have for a number of years."

Indeed, Staten also coached Celek's older brother, Eagles tight end Brent Celek, at the University of Cincinnati. And his more-accomplished brother was Garrett's lone claim to fame when he arrived in May as a struggling rookie: Left tackle Joe Staley said Garrett was generally referred to as Brent Celek's little brother.

Garrett Celek has since made a name for himself. And he hopes this season is just the beginning.

"I still need to improve in a lot of areas," Celek said. "I want to be one those key players that the quarterback can count on a big situation. I still have a lot of work to do."

Briefly: Wide receiver Michael Crabtree and running back Frank Gore were each fined $10,500 for throwing the football into the stands after scoring touchdowns in last week's win over Arizona. ... Defensive tackle Justin Smith (partially torn triceps) practiced for the second straight day without a non-contact jersey.

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